This application claims the priority of Korean Patent Application No. 2003-48431, filed on Jul. 15, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a wireless network, and more particularly, to a method and wireless communication system for providing Quality of Service (QoS), in a wireless network that communicates via a point-to-point network.
2. Description of the Related Art
A wireless network that communicates via a point-to-point network (called ‘Ad Hoc networking’) uses an autonomous communication system in which mobile wireless nodes set and maintain appropriate forwarding routes without managements or fixed network structures such as a center server and a repeater. Such a point-to-point wireless network is applicable to military purposes, police purposes, rescue purposes, and is also applicable to wireless communications used in home or office.
However, since wireless nodes are limited in their transmission ranges on the point-to-point wireless network, the respective nodes should perform a function that forwards data and also have a function which routes forwarding routes. Also, the wireless network should newly set forwarding routes according to movements of the respective nodes, unlike fixed networks. Furthermore, as requirements for QoS (Quality of Service) become higher, a wireless network satisfying QoS requirements such as delay, transmission capacity, jitter, etc., regardless of movements of respective nodes, is necessary.
To provide QoS in such a wireless network communicating via the point-to-point network, a related art routing protocol uses an In-band signaling method. This In-band signaling method is a method in which a transmitting node sets a forwarding route using a packet including QoS requirements in its IP header, and a receiving node reports the QoS states of nodes existing on the forwarding route to the transmitting node. If the transmitting node receives from the receiving node a message indicating that no node on the forwarding route satisfies the QoS requirements, the transmitting node searches for a new route satisfying the QoS requirements and newly sets a forwarding route. As a result, due to such repeated searches for a forwarding route, discontinuity exists in a packet transmission service and accordingly end-to-end delay is caused.